<template>
  <el-container class="home-container">
    <!-- 头部区域 -->
    <el-header>
      <div>
        <span>后台管理系统</span>
      </div>
      <el-button type="primary" @click="logout">退出</el-button>
    </el-header>
    <!-- 页面主体 -->
    <el-container>
      <!-- 侧边栏 -->
      <el-aside :width="isCollapse ? '64px' : '200px'">
        <div class="toggle-button" @click="toggleCollapse">|||</div>
        <!-- 侧边栏菜单区域 -->
        <!-- 
            unique-opened:是否只保持一个菜单的展开
            collapse：是否水平折叠收起菜单
            collapse-transition：是否开启动画
            router：是否使用 vue-router 的模式，启用该模式会在激活导航时以 index 作为 path 进行路由跳转
            default-active：当前激活菜单的 index
         -->
        <el-menu
          background-color="#333744"
          text-color="#FFF"
          active-text-color="#409eff"
          :unique-opened="true"
          :collapse="isCollapse"
          :collapse-transition="false"
          :router="true"
          :default-active="activePath"
        >
          <!-- 一级菜单 -->
          <el-submenu
            :index="item.id + ''"
            v-for="item in MenuList"
            :key="item.id"
          >
            <!-- 一级菜单模板区域 -->
            <template slot="title">
              <i :class="iconObjs[item.id]"></i>
              <span>{{ item.authName }}</span>
            </template>

            <!-- 二级菜单 -->
            <el-menu-item
              :index="'/' + subItem.path + ''"
              v-for="subItem in item.children"
              :key="subItem.id"
              @click="saveNavState('/' + subItem.path)"
            >
              <template slot="title">
                <i class="el-icon-menu"></i>
                <span>{{ subItem.authName }}</span>
              </template>
            </el-menu-item>
          </el-submenu>
        </el-menu>
      </el-aside>
      <!-- 内容主体 -->
      <el-main>
        <!-- 路由占位符 -->
        <router-view></router-view>
      </el-main>
    </el-container>
  </el-container>
</template>

<script>
export default {
  data() {
    return {
      MenuList: [],
      //每一个一级标题的ico图标
      iconObjs: {
        125: "el-icon-user-solid",
        103: "el-icon-s-tools",
        101: "el-icon-s-goods",
        102: "el-icon-s-order",
        145: "el-icon-s-data",
      },
      isCollapse: false,  //是否折叠
      activePath: '', //被激活的链接地址
    };
  },
  created() {
    this.getMenuList();
    this.activePath = window.sessionStorage.getItem('activePath')
  },
  methods: {
    logout() {
      window.sessionStorage.clear();
      this.$router.push("/login");
      this.$message.success("退出成功");
    },
    //获取菜单
    async getMenuList() {
      const { data: res } = await this.$http.get("menus");
      //console.log(res);
      if (res.meta.status !== 200) return this.$message.error(res.meta.msg);
      //获取成功的情况
      this.MenuList = res.data;
    },
    toggleCollapse() {
      //点击按钮切换菜单是否折叠
      this.isCollapse = !this.isCollapse;
    },
    saveNavState(activePath){
      //保存链接的激活状态
      window.sessionStorage.setItem('activePath',activePath)
      this.activePath = activePath
    }
  },
};
</script>


<style lang='less' scoped>
.home-container {
  height: 100%;
}
.el-header {
  background-color: #373d41;
  display: flex;
  justify-content: space-between;
  align-items: center;
  color: #fff;
  font-size: 22px;
  > div {
    display: flex;
    align-items: center;
  }
}
.el-aside {
  background-color: #333744;
  transition: all 0.3s;
  .el-menu {
    border-right: none;
  }
}
.el-main {
  background-color: #eaedf1;
}
.toggle-button {
  background-color: #4a5064;
  font-size: 10px;
  line-height: 24px;
  color: #fff;
  text-align: center;
  letter-spacing: 0.2em;
  cursor: pointer;
}
</style>